Ammonium adduct chemical ionization to investigate anthropogenic oxygenated gas-phase organic compounds in urban air
<p>Volatile chemical products (VCPs) and other non-combustion-related sources have become important for urban air quality, and bottom-up calculations report emissions of a variety of functionalized compounds that remain understudied and uncertain in emissions estimates. Using a new instrumenta...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/14377/2022/acp-22-14377-2022.pdf |
| Summary: | <p>Volatile chemical products (VCPs) and other non-combustion-related sources
have become important for urban air quality, and bottom-up calculations
report emissions of a variety of functionalized compounds that remain
understudied and uncertain in emissions estimates. Using a new instrumental
configuration, we present online measurements of oxygenated organic
compounds in a US megacity over a 10 d wintertime sampling period, when
biogenic sources and photochemistry were less active. Measurements were
conducted at a rooftop observatory in upper Manhattan, New York City, USA
using a Vocus chemical ionization time-of-flight mass spectrometer, with
ammonium (NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="12pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="f310eaa25b6021a3131a6b16c503ac9d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-14377-2022-ie00002.svg" width="12pt" height="15pt" src="acp-22-14377-2022-ie00002.png"/></svg:svg></span></span> as the reagent ion operating at 1 Hz. The range of
observations spanned volatile, intermediate-volatility, and semi-volatile
organic compounds, with targeted analyses of <span class="inline-formula">∼150</span> ions, whose
likely assignments included a range of functionalized compound classes such
as glycols, glycol ethers, acetates, acids, alcohols, acrylates, esters,
ethanolamines, and ketones that are found in various consumer, commercial,
and industrial products. Their concentrations varied as a function of wind
direction, with enhancements over the highly populated areas of the Bronx,
Manhattan, and parts of New Jersey, and included abundant concentrations of
acetates, acrylates, ethylene glycol, and other commonly used oxygenated
compounds. The results provide top-down constraints on wintertime emissions
of these oxygenated and functionalized compounds, with ratios to common
anthropogenic marker compounds and comparisons of their relative abundances
to two regionally resolved emissions inventories used in urban air quality
models.</p> |
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| ISSN: | 1680-7316 1680-7324 |